华中科技大学夏宝玉团队报道了质子交换膜系统中持久的CO₂转化。相关研究成果于2024年1月31日发表在《自然》。

原则上，将二氧化碳（CO₂）还原为有用化学物质的电解可以促进更可持续发展和碳中和。然而，将其发展成为一个稳健的过程仍然具有挑战性，因为有效的转化通常需要CO₂以碳酸盐形式沉淀的碱性条件，这限制了碳的利用和系统的稳定性。物理清洗、脉冲操作和使用偶极膜等策略可以部分缓解这些问题，但不能完全解决这些问题。因此，在不形成碳酸盐的酸性电解质中进行CO₂电解已被探索为最终更可行的解决方案。

该文中，研究人员开发了一种质子交换膜系统，该系统在源自废铅酸电池的催化剂上将CO₂还原为甲酸，其中晶格碳活化机制起作用。当将CO₂还原与氢氧化相结合时，甲酸的法拉第效率超过93%。该系统与启动/关闭过程兼容，在600mAcm^-2的电流密度和2.2V的电池电压下，实现了近91%的CO₂单程转换效率，并可连续运行5200h以上。

研究预计，通过使用坚固高效的催化剂、稳定的三相界面和耐用的膜，这种卓越的性能将有助于推动碳中和技术的发展。

附：英文原文

Title: Durable CO2 conversion in the proton-exchange membrane system

Author: Fang, Wensheng, Guo, Wei, Lu, Ruihu, Yan, Ya, Liu, Xiaokang, Wu, Dan, Li, Fu Min, Zhou, Yansong, He, Chaohui, Xia, Chenfeng, Niu, Huiting, Wang, Sicong, Liu, Youwen, Mao, Yu, Zhang, Chengyi, You, Bo, Pang, Yuanjie, Duan, Lele, Yang, Xuan, Song, Fei, Zhai, Tianyou, Wang, Guoxiong, Guo, Xingpeng, Tan, Bien, Yao, Tao, Wang, Ziyun, Xia, Bao Yu

Issue&Volume: 2024-01-31

Abstract: Electrolysis that reduces carbon dioxide (CO2) to useful chemicals can, in principle, contribute to a more sustainable and carbon-neutral future1,2,3,4,5,6. However, it remains challenging to develop this into a robust process because efficient conversion typically requires alkaline conditions in which CO2 precipitates as carbonate, and this limits carbon utilization and the stability of the system7,8,9,10,11,12. Strategies such as physical washing, pulsed operation and the use of dipolar membranes can partially alleviate these problems but do not fully resolve them11,13,14,15. CO2 electrolysis in acid electrolyte, where carbonate does not form, has therefore been explored as an ultimately more workable solution16,17,18. Herein we develop a proton-exchange membrane system that reduces CO2 to formic acid at a catalyst that is derived from waste lead–acid batteries and in which a lattice carbon activation mechanism contributes. When coupling CO2 reduction with hydrogen oxidation, formic acid is produced with over 93% Faradaic efficiency. The system is compatible with start-up/shut-down processes, achieves nearly 91% single-pass conversion efficiency for CO2 at a current density of 600mAcm2 and cell voltage of 2.2V and is shown to operate continuously for more than 5,200h. We expect that this exceptional performance, enabled by the use of a robust and efficient catalyst, stable three-phase interface and durable membrane, will help advance the development of carbon-neutral technologies.

DOI: 10.1038/s41586-023-06917-5

Source: https://www.nature.com/articles/s41586-023-06917-5